<html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <script>
        cook = document.cookie;
        if(!cook){
            document.cookie="cookie"
        }else {
            alert(cook)
            document.cookie=cook+1
        }
    </script>
</head>
<body>
    <h1 style="color: green;width:200px;height: 300px" onclick="showAlert()"> 点击后五秒出现提示框（写法好像不对，时钟即时弹出来）</h1>
    <h1 style="color: green;width:200px;height: 100px" onclick="clear()"> 清除延时</h1>
</body>
</html>